Hearing devices must be adjusted prior to their use. To this end, they are calibrated in a defined acoustic environment. For this purpose, a so-called measuring box is generally used, the main task of which consists in attenuating ambient noises. A successful and reliable measurement is actually only possible by means of this noise attenuation.
Measuring boxes are usually designed such that the ambient noises are “screened out” by means of the mass and impermeability of the respective box. A passive attenuation thus takes place. This nevertheless leads to excessively large and heavy measuring boxes. In the case of smaller measuring systems, such as can be found in hearing device measuring systems for hearing device acousticians, adequate attenuation of the ambient noises is not possible as a result of the required minimal installation size and mass of the measuring box used there.